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EKOS FITS Viewer Issue

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Hi folks,


I use my Raspberry 4 with astroberry (EKOS/KStars) since roughly summer 2020. I never updated anything and it worked fine for me. I always use a Canon600Da as imaging camera and since day one I saved the files as RAW (cr2) on the SD card of the Raspberry. Reason for RAW is that I usualy took at least the dark only with the camera in a box. So those are always Cr2. And I heard some issues that sometimes PixInsight stated that the fits lights and Cr2 darks are not the same size resolution wise. To avoid that I took all my pics in RAW format.

Due to an issue I got with a new ASI178MM I wanna use for vids with firecapture I decided to update the whole system to the newest version.
So since this update a few weeks ago I use KStars Version 3.5.5 with Build 2021-10-10T01:43:20Z as it says in the info section.

So whats my problem? First let me explain how I use the Fitsviewer in the past and what I remember to see in the old version
Usualy I got a Black and white (unbayered) picuture and a not stretched view. I than used the histogram to roughly set the exposure to the first 1/3 of the histo. That was my workflow and it worked :)

Since the update I recognized thats the Fits Viewer shows colours. No big deal. But at the first night out it also seems that my exposure and ISO changes has no effect on the picture FitsViewer showed me. 
So it was some kind of guess work and my experience to set my exposure to the correct point.

Yesterday I took some time and tried to investigate the issue. I know that there are the option to setup the FitsViewer and believe my I checked and unchecked them all but that changed nothing.
Below I uploaded two pictures of the last night I used my gear. Both pichtures are made under the same conditions just a few minutes apart. I loaded them into the viewer to demonstrate you what happens

Pic 1:
180s / ISO 1600 Also visible are the fits viewer options. No auto stretch, no auto debayer are the most important ones. Also the stretch button in the lower left corner is inactive. So it should be the linear version of the CR2 file as it was in the past.

 

Pic2:
240s / ISO400! Believe it or not this image should be way darker than the first one (~60s ISO1600 equivalant vs. 180s ISO 1600). But in the fits view they look identicaly as a stretch is applied. Also, and this is much worse, the histogram looks very similar but not identicaly.

 

To be honest I have no clue what is going on. I would be happy to get some ideas how to approach that issue. I am not very familiar with linux so If you need something out of the system it would be great if you also can tell me where to find the stuff.

Clear skies
Andreas
 
2 years 5 months ago #76954
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Replied by Jasem Mutlaq on topic EKOS FITS Viewer Issue

Hello Andreas, welcome to INDI forum!

Please check "Non-Linear Histogram" in the options and hopefully that would help.
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2 years 5 months ago #76960

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Replied by Andreas on topic EKOS FITS Viewer Issue

Hi Jasem,

thanks for your answer. I already tried the non linear histogram as well as forcing fits viewer to open each pic in a different tab to force the histogram to update. Both things did not work.
Also changing from Cr2 (RAW/Native) to fits did not change the strange histogram behaviour. 

Regards
Andreas
 
 
2 years 5 months ago #76964

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Replied by Maria on topic EKOS FITS Viewer Issue

Hi Jasem,

Yes I have noticed this issue too.
Unfortunately setting the "Non-Linear Histogram" option when using Native or Fits capture with a DSLR still results in a histogram with a 0-255 X-axis range.

Another bug I noticed also is when using my ZWO 294 or 183 and capturing in FITS mode as normal, with the "Single Preview Tab" enabled, the histogram does not update between new exposures.

I noticed this change since 3.5.3 and 3.5.4/3.5.5. It was working as you would expect in v3.5.3.

Hope we can track down the source of these two bugs.

Always, thanks for your help.
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2 years 5 months ago #76965

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Replied by Paul on topic EKOS FITS Viewer Issue

Andreas,

Just wondering if you have the stretch on or off?

Paul
2 years 5 months ago #76977

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Replied by Andreas on topic EKOS FITS Viewer Issue

Hello Paul,


as visible in the screenshot there is no stretch applied on purpose. Means the button on the lower left isnt pushed and the autostretch option is also off.
So there is nothing I can undo in terms of stretching.
But both pictures are obviously stretched somehow because they look absolutely identically even they are different un exposure and open them in a usual raw viewer also shows me different pictures and histograms.
Hope that answers your question as detailed as possible.

CS
Andreas
 
2 years 5 months ago #76983

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Replied by Jasem Mutlaq on topic EKOS FITS Viewer Issue

For CR2, the reason you see 8bit only is because it converts to jpg to show in the viewer and that's 8 bit per channel.

For FITS, it should work as expected.
2 years 5 months ago #76985

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Replied by Andreas on topic EKOS FITS Viewer Issue

Hello Jasem,

I tried fits yesterday and Maria is my witness it did not work. I still got an 8 bit histogramm. 
I know it is a weird problem and Maria help me a lot yesterday via screensharing but we were not able to got a matching histogram which clearly represents both pictures.

If you need additional information or even the two raw files I used to create my screenshots in my first post let me know

CS
Andreas
2 years 5 months ago #76986

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Replied by Jasem Mutlaq on topic EKOS FITS Viewer Issue

Sure, please post a link to them and I'll check them out.
2 years 5 months ago #76992

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Replied by Andreas on topic EKOS FITS Viewer Issue

Hi Jasem,


uploaded both raws to my onedrive. I hope that works for you. Thanks for taking a look at the issue.

180s ISO1600
240s ISO400

CS
Andreas
2 years 4 months ago #77023

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Replied by Jasem Mutlaq on topic EKOS FITS Viewer Issue

Ah CR2, as I said above. It's 8bit because KStars internally converts this to JPEG which is 8bit per channel.
2 years 4 months ago #77037

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Replied by Andreas on topic EKOS FITS Viewer Issue

Okay but is it the 8bit conversion which makes them look so identical? In this way it is useless to determine if the exposure is correct. 
FITS is no option for me because at least the dark frames are taken with the camera alone and so they are always CR2 files.
 
2 years 4 months ago #77079

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